1. Field of Invention
This invention relates generally to computer networks and network security, and more particularly to a method, apparatus, signals, and medium for managing a data transfer on a data network.
2. Description of Related Art
The rapid expansion of high-speed Internet connections and the use of the World Wide Web for commerce, entertainment, and education has provided significant benefits to the global user community. The wide-spread, low cost, and continuous availability of web-based information services has resulted in developments ranging from new business models to portals which provide access to government and education services, to the rapid and free exchange of ideas and information for all members of the Internet community.
Companies have come to increasingly rely on their internal and external networks for information dissemination, service delivery, communications, and data storage, for example. Companies have become particularly vulnerable to disruptions to both internal and external network services. Such disruptions may occur from, for example, malicious code such as computer viruses that may be transmitted via email or other file transfers from an external network. Companies may also need to protect sensitive information in their internal network from access by unauthorised users. At the same time companies have to deal with an ever increasing number of communication and file transfer services, such as instant messaging and peer-to-peer file sharing. The use of such services by employees of a company may expand to occupy a substantial portion of available bandwidth in a company network. Much of the traffic may be frivolous communication, while at the same time distracting workers from assigned tasks.
There is thus a desire to exercise some control over such traffic in both internal and external networks. For example, company policy may dictate that all instant messaging and peer-to-peer traffic between any computer on the company network and any computer outside the company network must be subject to one or more policy rules. Such policy rules may include completely blocking access to certain applications.
Similarly, there may also be a need to monitor and control non-frivolous work-related communications and other data transfers, which may inadvertently subject the internal company network to viruses, intrusion attempts or other unauthorised uses.
While such monitoring and controlling of traffic is in many instances highly desirable, such processes may require the provision of additional computer resources. Depending on the company's network management policies, the monitoring and controlling of data transfers may place a substantial overhead on the operation of the network and may result in unacceptable delays in transferring data from internal to external networks, particularly where there are a large number of network management policies in place.